Our overall objective is to improve the diagnostic quality of chest radiography with a specialized scanning system. Common chest radiographs pose a severe challenge to conventional radiographic imaging systems due to the wide variation in patient absorption over the radiographic field. Typically the film is taken to optimally expose the lung field, which leaves the area of the mediastinum, diaphragm and heart underexposed, resulting in poor image contrast in these areas. Our solution to this technical limitation is to use large beam of x-rays (2 centimeters by 2 centimeters), scanning in raster pattern over the patient's chest to expose a conventional film cassette. The patient attenuation at each point is measured with a suitable detector and the results of these measurements are used to adjust the x-ray tube output so as to optimally expose the film at each point over the entire image. The system is designed to complete this scanning process in 5 seconds making approximately 1500 attenuation measurements over the entire film. The system uses a microprocessor to orchestrate the motion of the scanning beam and is an active component in the feedback system between the attenuation measurements and x-ray output. The system as it is currently designed is capable of rejecting unwanted scatter radiation from the patient without the use of a radiographic grid and accordingly we expect improved contrast from this fact alone. To date, we have completed design, construction and assembly of the various system components of this scanner and are starting to form images of simple objects to understand its imaging properties. During the next year of our program, we will do controlled perception experiments with this scanning device to compare its relative merits to conventional film radiography.